Connector



Oct. 2, 1962 w. J. sco'r'r 3,056,851

CONNECTOR Filed Dec. 3, 1959 IN V EN TOR.

nit tates atent r 3,055,851 CONNECTOR William J. Scott, Sycamore, ill,assignor to ideal industries, Inc., Sycamore, llll., a corporation ofDelaware Filed Dec. 3, 1959, Ser. No. $57,099 it Claims. (3. l'7 i-=-8i)This invention is in the field of connectors of the screwon type and isa new and improved insulating cap with a connecting structure,constructed and arranged to be turned or screwed down over the strippedends of a plurality of electric wires, for example, two or more, eitherstranded and/ or solid, of the same or different sizes, or otherwise.

A primary object of the invention is a new and improved electricalconnector of the screw-on type.

Another object is a connector having a cap of a stifily flexiblematerial constructed so that the stripped ends of the wires beingconnected will not pierce, penetrate or damage the end of the cap.

Another object is a connector protected against the stripped ends of thewires puncturing the end of the cap but without complicating manufactureor assembly.

Another object is a connector structure with a guide for the strippedends of the wires to prevent the cap from being damaged or pierced.

Other objects will appear from time to time in the ensuing specificationand drawings in which:

FIGURE 1 is a plan view of the connector;

FIGURE 2 is an end view; and

FIGURE 3 is a section along line 33 of FIGURE 2.

In the drawings, the connector has been shown with an insulating cap orcover which has been indicated generally at it) and may include agenerally cylindrical body or shell 12 closed at one end by an end wall14, which is preferably integral with the cap and generally open at theother end at 16, providing what shall be termed a generally open centralbore 18. The bore of the cap or coil houses or encloses a wire coil 2tFor purposes of illustration, the coil has been shown generally taperedwith a large end 22, adjacent the open end of the cap and a small end 24adjacent the closed end.

I may provide an enlarged or thickened portion 26 in the cap or shellgenerally at the open end which may be formed with a threaded innersurface or relief surface 28 on the inside, although this is notnecessary. The threads may be molded directly into the inside, and thelarge end 22 of the coil meshes into the groove of the threads. I preferto make the cap or shell out of nylon, or polyethylene, or any othersuitable thermoplastic material which is tough but somewhat resilientand at the same time is a good dielectric and suitable for hightemperature use.

The inner surface of the bore may remain somewhat cylindrical from theopen end toward the end wall but the intermediate or middle turns of thecoil have been shown as decreasing in diameter, or tapered, as at 29, so

that a clearance or spacing is provided at 30 throughout the majority ora substantial portion of the length of the coil with respect to theinner surface of the cap, although this is not necessary. This provideswhat is referred to as a free spring connector.

An extended and possibly distended turn 32 may be provided adjacent thesmall end of the coil to serve as a guide or pilot for the small end tocenter it relative to'the axial bore of the cap. The spacing, shown at36, is not totally necessary and the coil may have a uniform pitchthroughout its length.

The end at of the coil may be extended slightly or pulled away from thenormal turns of the coil and an abutment 38 may be provided in or as anintegral part Patented Oct. 2, 1962 of the shell or cap to function as ashoulder or anchor for the end of the coil. This abutment or shouldermay be of a suitable formation but it is preferred that it oppose theend of the coil to resist the normal rotative tendency of the coil, whenthe connector is being turned down over the stripped ends of a pluralityof wires. The abutment may be a separate metal insert, but I find iteasier to mold it as an integral part. The end 34 of the coil might beblunt, turned in or back, or otherwise suitably shaped, to engage theabutment regardless of its particular size, shape or disposition.

The open end of the cap may be provided with an enlarged, preferablyintegral skirt 40, which may be cylindrical and well rounded, as at 42,where it joins the shell or cap to function as a guide or funnel andalso as a skirt to prevent arcing to a ground.

The end wall of the cap at the closed end of the bore is offset, as at44, and moves into a tapered socket or cavity 36 behind the abutment 38.The depth of the socket 46 or cavity may varysomewhat and I position asteel or metal ball or sphere 48 in the form of an insert next to or inthe socket which, as shown, has an outside diameter slightly greaterthan the inside diameter of the throat 5d of the coil to prevent theball orsphere from coming out. As shown in FIGURE 3, the ball may fitloosely within the large or expanded turn 32 of the coil which pilots orcenters the coil in the rear end of the cap.

The socket has a tapered inner wall 52 which is closed off by a rearwall 54 which has a diameter less than the ball diameter 48. Since thesocket is tapered, it enlarges forwardly and the inside diameter of thesocket at its entrance, say at the beginning of ofiset 44, is on theorder of and possibly slightly greater than the ball diameter. Or itmight be slightly less. But, in any event, the material is sufficientlydistortable or flexible so that when the ball is pushed toward thesocket, the sides will flex out somewhat at the socket entrance, and theball may be forced in. The object of this is that when the stripped endsof the wires move through the throat 50 and contact the ball, thepressure developed will force the ball into the tapered socket where itwill seat firmly. Thereafter, if the connector is backed off of thewires, the ball will stay in the socket.

This has the advantage that a connector of this type in use expands thethroat 50 of thecoil. The throat may taken an enlarged set and couldopen up sufiiciently so that the ball would otherwise fall out. But thiscan only occur after the connector has been used at least once andpossibly more. And when the connector has been used the ball will havebeen forced into the socket and will stay in place.

The use, operation and function of the invention are as follows:

therein in a suitable manner. The cap and coil, as a unit,

are then screwed down on the stripped ends of a plurality of electricWires in a known manner. The coil functions like threads so that the capand coil automatically feed down on the stripped ends of the wires andwill compress the wires together and form grooves or threads thereoncorresponding to the coil. The coil is interlocked to the cap so thatwhen the cap is rotated, the coil will also be rotated.

When the coil is screwed down on the Wires, the stripped ends willeventually pass completely through the coil and will engage the end wallof the cap. The ends of the wires have normally been cut or snipped withelectricians pliers or the like and are sharp or jagged. When thestripped ends contact the end wall of the cap, if the cap is thereafterturned an appreciable amount, the sharp ends of the wires may rip ordrill through or otherwise mar the end wall which is plastic.

To prevent this, I position a ball insert or sphere or spherical objectin the cavity or socket between the end of the coil and the end wall ofthe cap which functions as a deflector or guide, as well as a shield,for the end wall. This is to say that in addition to preventing directcontact between the sharp ends of the wires and the end wall, the

spherical object will deflect or guide the stripped ends in an outwarddirection and at the same time will bend the ends of the wires into ahelical or circumferential direction so that even if the stripped endswere extended and could get past the sphere, they would not contact theend wall. At the same time, the stripped ends will pass between thethroat of the coil and the forward convex face of the sphere and willbecome tightly interlocked resisting withdrawal.

In a connector of the particular type shown, the throat of the coil willexpand when the stripped ends of the wires are inserted and in allprobability will eventually come to an inside diameter which is greaterthan the outside diameter of the sphere. But this is of no consequencesince the presence of the wires will prevent the sphere from coming out.

The use of a ball has the advantage that, in assembly, it does not haveto be oriented. The ball can be merely dropped within the cap and thenthe spring may be in serted and turned into place until it is fullyseated. The ball in no way interferes with the drive or interlockbetween the cap and coil since the abutment 38 is radially outside ofthe circumference of the ball. The ball may be totally free in thesocket between the inner end of the coil and the end wall of the cap.But since its diameter is greater than that of the throat of the coil,it cannot get out. The ball has the additional advantage that it willrotate when contacted by the stripped ends of the wires and will providea distributed area of contact under the thrust of the stripped ends,thereby spreading the load and preventing a failure. The ball does nothave to be truly spherical but I want it to be self-orienting.

The ball may be simply dropped into the cap during manufacture and thenthe coil is screwed in and assembly is complete. In this condition theball will be loose. But once the connector has been used the ball willbe forced into the tapered socket and will thereafter stay in place.

It should be noted that the spacing is such that when loose, the ball issufficiently behind the last turns of the spring, as at 24 and 50, sothat a certain amount of cavity behind the throat 50 is available toaccept the stripped ends of the wires when they come through the throat.In effect, I provide a certain amount of cavity behind the spring toallow for some misalignment of the wires. This also allows the connectorto hold on to the minimum combinations. The ball is free prior to use ofthe connector and will actually rattle around a bit. But when theconnector is turned upright with the bore up and the ball resting on theinlet of the tapered socket, there will be sufficient spacing betweenthe top of the ball and the throat 70 such that the stripped ends of thewires can work their way in during assembly.

Since the ball is round, it deflects the wires on an angle other thanwhat the connectors would ordinarily take. In fact, the wires actuallybend around and become interlocked behind the coil. 7

While I have shown and described the preferred form and suggestedseveral variations of my invention, it should be understood that severaladditional modifications, substitutions, alterations and changes may bemade without departing from the inventions fundamental theme. The crosssection of the wire may be round, square, or otherwise. I mentionednylon as the material of the cap but it might be any other suitablematerial. With these and other modifications in mind, I wish that theinvention be unrestricted, except as by the appended claims.

I claim: a

1. In an article of manufacture, a connector for joining the strippedends of two or more electric wires and the like, including a cap of astifiiy flexible plastic material capable of being penetrated by thewire ends with a generally central bore open at one end and closed by anend Wall at the other end, a generally cylindrical wire coil in thebore, an insert having the general shape of a sphere positioned betweenthe inner end of the coil and the end wall of the cap and having adiameter greater than the inside diameter of at least a part of thecoil, and means for holding the coil in the bore.

2. The structure of claim 1 further characterized in that the sphere isconfined between the end wall of the cap and the inner end of the coil,and is otherwise free for movement.

3. The structure of claim 1 further characterized in that the inner endof the coil is provided with an enlarged turn and with a reduced turnforwardly thereof toward the open end of the cap to define a partialsocket opposite and spaced somewhat from the sphere.

4. The structure of claim 1 further characterized in that the sphere hasan outside diameter which, while greater than the inside diameter of atleast a part of the coil, is less than the inside diameter of the bore.

5. The structure of claim 1 further characterized in that the end wallof the cap is formed into a socket inside the cap accepting the sphere.

6. The structure of claim 1 further characterized in that the end wallof the cap is formed into an inner tapered socket, the entrance to thesocket opening into the bore of the cap and having an initial diameteron the order of the diameter of a sphere such that when the connector isscrewed down on the stripped ends of a plurality of electric wires andthe wires contact the sphere and push it into the socket, the spherewill become lodged in the socket in a tapered press fit.

7. In an article of manufacture, a connector for joining the strippedends of two or more electric wires and the like, including a cap of astifily flexible plastic capable of being penetrated by the wire endswith a generally central bore open at one end and closed at the otherend by an end wall, a generally cylindrical wire coil in the bore, aninsert positioned freely between the inner end of the coil and the endwall and having a circular exterior with an outside dimension greaterthan the inside dimension of at least a part of the coil, and means forholding the coil in the bore.

8. In an article of manufacture, a connector for joining the strippedends of two or more electric wires and the like, including a cap of astifily flexible plastic capable of being penetrated by the Wire endswith a generally central bore open at one end and closed at the otherend by an end wall, a generally cylindrical wire coil in the bore, theend wall of the cap being formed into an inner socket, one end of thesocket opening in the bore of the cap, and an insert positioned freelybetween the inner end of the coil and the socket in the cap and havingan outside dimension slightly greater than at least a portion of thediameter of the socket such that when the connector is screwed down onthe stripped ends of a plurality of electric Wires and the Wires contactthe insert and force it toward the socket, the insert will become lodgedin the socket in a press fit.

9. In an article of manufacture, a connector for joining the strippedends of two or more electric wires and the like, including a cap of astiffly flexible material otherwise capable of being penetrated by thewire ends with a generally central bore open at one end and closed by anend Wall at the other end, a generally cylindrical wire coil in thebore, means for holding the coil in the bore, and a deflector in thebore at the end wall for preventing the wire ends from penetrating theend wall having an outside dimension appreciably less than the insidedimension of the bore at the end wall.

5 6 10. The structure of claim 9 in which the deflector is 2,199,532Weeks May 7, 1940 in the form of an insert formed separartely from mhecap 2,308,286 Joyce Jan. 12, 1943 and coil. 2,890,266 Bollmeier June 9,1959 3,001,002 Schinske "0-- Sept. 19, 196 1 References Cited in thefile of this patent 5 FOREIGN PATENTS UNITED STATES PATENTS 2,110,45Applegate 3, 19-33 2721928 Switzerland P 1951

